Inserted blade cutter



F. P. MILLER INSERTED BLADE CUTTER Filed March 4, 1941 Jm. as, 1943.

FRANK JP,- Mum Patented Jan. 26, 1943 Darren res ()FFICE 6 Claims.

This invention relates to the art of milling cutters and the like, and particularly to means for rigidly locking inserted blades in a metal cutting tool.

It is desirable, especially in roto-mill operations, that the maximum possible number of blades for a given size cutter be inserted in the cutter body. The use of separate blade locking elements such as screws, wedges, pins and the like necessarily demands space that could profitably be occupied by additional blades, and of course, the multiplicity of individual adjustments militates against uniformity. In a well known prior art cutter, separate locking elements have been eliminated :by the expedient of tapering the blades and driving them into their seats, but such construction is expensive, and it is a practical impossibility that all blades will seat uniformly. The most desirable type of blade, both from the standpoint of economy in manufacture and durability, is one that is rectangular in cross section, but separate and space-taking lock means has heretofore been necessary to its use.

An object of the present invention is to provide a novel blade arrangement for inserted blade cutters, wherein certain of the blades themselves are employed as a means of locking the remainder of the blades in fixed position in a cutter body, thus effecting double function for the blades which serve as locking elements, and permitting use of the maximum possible number of blades for any given size cutter.

Another object is to provide a novel method of locking inserted cutter blades in positions of adjustment in a cutter body.

Other objects and advantages will be readily apparent to those skilled in the art.

In the accompanying drawing:

Figure 1 is a fragmentary face View of a cutter body with blades positioned therein;

Figure 2 is a fragmentary peripheral elevation of a cutter with blade receiving slots therein;

Figure 3 is a vertical section on the line 3-3 of Figure 1;

Figure 4 is a vertical section on the line 4-4 of Figure 1;

Figure 5 is a fragmentary section through a blade as seated in one form of blade receiving slot;

Figure 6 is a fragmentary peripheral elevation of a cutter body provided with a tapered blade receiving slot;

Figure 7 is a face view of the body and slot shown in Figure 6;

Figure 8 is a perspective view of one of the cutter blades of rectangular cross section;

Figure 9 is a perspective view of one of the tapered blades used also as a locking element;-

Figure 10 is a fragmentary face view of a cutter body provided with an alternative form of blade slot, with a blade indicated therein in dotted lines.

In the practice of the invention a cutter body I! is provided around its periphery with a series of closely arranged blade receiving. slots I2 and IS. The slots l2 are numerically greater than the slots l3, and are formed with parallel side walls to receive inserted cutter blades ll of rectangular cross section, as shown in Figure 8. The trailing wall of each slot is provided with parallel longitudinal serrations l5 which mesh with interfitting, similarly arranged serrations It on the adjacent trailing face of the blade. The slots l2 are of uniform width from end to end, and open at their ends to opposite faces of the cutter body, The blades M are likewise of uniform width, and are inserted end-wise into their respective slots l2 at desired points of adjustment both radially and axially of the cutter body as determined by engagement of the serrations I5 and I6.

The slots [3 are tapered longitudinally on at least one side wall to receive complemental tapered cutter blades I! which, in seating, are driven into the slots with a wedge action that expands the metal of the cutter body laterally on opposite sides of the slot. Like the slots l2 and blades It, the trailing walls of the tapered slots l3 are provided with adjustment serrations I8 that interfit with complemental serrations [9 on the adjacent face of each blade H.

The respective slots are so arranged that every third slot is tapered, being spaced from the next tapered slot by two intervening uniform width slots l2. Thus when all blades are Positioned in their respective slots and the tapered wedge blades ll are driven home, the segments [3a of the cutter body on opposite sides of each slot l3 will be crowded over .laterally into tight clamping engagement with the adjacent uniform width blades M, so that all blades are tightly 'and firmly held in locked positions of adjustment.

To facilitate the shift of the clamping seg ments l3a under the separating action of the wedge blades ll, the metal of the cutter body is relieved by the provision of enlarged rounded bottoms 25 over the full length of each slot, or, as shown in Figure 10, a separate slot 2| of lesser width may extend along the bottom of each slot substantially radially into the cutter body.

By practice of this invention, it is assured that a greater number of blades may be employed in any given size cutter than would be possible if separate wedging devices and locking elements were used. It is also assured that at least twothirds of the blades will be positioned in their slots exactly at desired points of adjustment, for the blades do not shift in the locking operation; and the predominance of the plain rectangular cross section blades renders the assembly highly efiicient and economical.

I claim:

1. In an inserted blade cutter, a cutter body having a plurality of closely spaced substantially parallel blade receiving slots therein, certain of said slots being tapered and the others being of uniform width from end to end, cutter blades insertable in said slots and complemental to their respective slots, and the tapered blades serving also as wedges acting on the material of the cutter body to clamp same against the nontapered blades whereby to look all blades in position in the cutter.

2. In an inserted blade cutter, a pair of substantially parallel blade slots of rectangular cross section and uniform width from end to end, a complemental blade in each slot, a longitudinally tapered blade slot interposed between the uniprising longitudinally tapered slots interposed between pairs of the uniform width slots, and tapered blades driven into said tapered slots whereby to wedge the material of the cutter body into firm holding engagement against the blades in the uniform width slots.

4. In an inserted blade cutter, a series of substantially parallel blade slots of uniform width from end to end, a complemental blade insertable in each slot, longitudinally tapered blade slots interposed at intervals between adjacent uniform width slots, tapered blades insertable in said tapered slots for wedging engagement therein to wedge the intervening material of the cutter body into locking engagement against the blades of the adjacent uniform width slots, and all said slots and blades having at least on their trailing side faces and walls interfitting serrations extending longitudinally of the blades and slots at an angle convergent to the axis of the cutter body.

5. In an inserted blade cutter, a series of substantially parallel blade slots of uniform width rom end to end, a complemental blade insertable in each slot, longitudinally tapered blade slots interposed at intervals between adjacent uniform width slots, the material of the cutter body being relieved beneath each slot over the full length thereof, and tapered blades insertable in said tapered slots for wedging engagement therein whereby to wedge the intervening material of the cutter body into locking engagement against the blades in the uniform width slots.

6. In an inserted blade cutter having a series of closely spaced substantially parallel blade slots with blades insertable therein, the method of locking all blades in positions of adjustment which comprises providing substantially every third slot as a tapered slot distinctive from the remainder, and driving a complemental tapered blade in each tapered slot as a wedge forcing the intervening material of the cutter body into clamping engagement with the blades in adjacent slots.

FRANK P. MILLER, 

